1. Technical Field
The present disclosure relates to a thermal spray powder used for forming a thermal spray coating having abradability, a method of forming an abradable thermal spray coating using the same, and an abradable thermal spray coating.
2. Description of Related Art
In thermal spray coatings having abradability (abradable thermal spray coatings), materials having certain specifications have been used based on standards for aircraft engines and the like. Here, abradability is a characteristic in which a material is worn down itself to protect a mating member. In recent years, for example, in gas turbines and jet engines, abradable thermal spray coatings having heat resistance exceeding a heat resistance temperature of, for example, 500° C., have been developed.
For example, in Japanese Patent Application Publication No. 10-140318 (JP 10-140318 A), the following method of forming an abradable thermal spray coating is disclosed. In the forming method, first, a Ni-5Al or Ni-18.5Cr-6Al powder is plasma thermally sprayed onto a surface of a base material. Next, a powder obtained by mixing the following first powder and second powder is flame thermally sprayed onto the plasma thermally sprayed surface. The first powder includes Cr at 3 to 7 weight %, Al at 3 to 7 weight %, Al2O3 and SiO2 at 6 to 14 weight %, and Ni at the remaining weight %. The second powder includes Cr at 3 to 7 weight %, Al at 3 to 7 weight %, Al2O3 and SiO2 at 15 to 30 weight % and Ni at the remaining weight %.